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Quantitative elution of acidic and neutral glycolipids of brain and spinach leaves from silicic acid columns with acetone was demonstrated. Cerebrosides and sulfatides of brain and sulfolipid and glycosyl diglycerides of spinach leaves were eluted quantitatively with acetone while prospholipids
UDP-sulfoquinovose synthase, SQD1, catalyzes the transfer of sulfite to UDP-glucose giving rise to UDP-sulfoquinovose, which is the head group donor for the biosynthesis of the plant sulfolipid sulfoquinovosyldiacylglyerol. The native SQD1 enzyme of spinach exists as a 250 kDa heteroprotein complex
Spinach chloroplasts were purified on gradients of Percoll which preserved envelope impermeability and CO2-dependent oxygen evolution in the light. Application of (35)SO4″ to purified chloroplasts resulted in a light-dependent labeling of a lipid component which was indentified as sulfoquinovosyl
Incubation of intact spinach (Spinacia oleracea L.) chloroplasts in the presence of (35)SO(4) (2-) resulted in the light-dependent formation of a chloroform-soluble sulfur-containing compound distinct from sulfolipid. We have identified this compound as the most stable form (S(8)) of elemental
A galactolipid lipase from primary bean (Phaseolus vulgaris) leaves has been used to partially deplete spinach chloroplast inner membranes of their galactolipids. Chloroplasts treated with the lipase in the absence of bovine serum albumin lost 91% of their monogalactosyl diglyceride, 83% of their
A lipid requirement for photosystem I activity in Spinacia oleracea chloroplasts has been characterized. The transfer of electrons from tetramethyl-p-phenylenediamine through the chloroplast photosystem to viologen dye was used as an assay of photosystem I activity. Activity is diminished by
Using a subcellular-specific proteomic approach, we have identified by protein microsequencing, a putative 35-kDa annexin from among the chloroplast envelope polypeptides. To confirm this identification, we demonstrate that (a) a 35-kDa protein, identified as annexin by antibody cross-reactivity,
The sulfolipid sulfoquinovosyldiacylglycerol is a component of plant photosynthetic membranes and represents one of the few naturally occurring sulfonic acids with detergent properties. Sulfolipid biosynthesis involves the transfer of sulfoquinovose, a 6-deoxy-6-sulfoglucose, from UDP-sulfoquinovose
Sulfoquinovosyldiacylglycerol is a polar lipid present in photosynthetic membranes. It contributes to the negative surface charge of the membrane and plays a pivotal role under phosphate stress. The SQD1 protein is the key enzyme involved in the formation of the sulfolipid head group precursor,
BACKGROUND
Sulfoquinovosylmonoglycerides (SQMG) and sulfoquinovosyldiglycerides (SQDG) in the lipid extracts of parsley (Petroselinum crispum) and spinach (Spinacia oleracea) leaves were investigated. The aim of this work was to assess and establish the chemical characterization of fatty acyl chains
6-Sulfo-alpha-D-quinovopyranosyl phosphate was reacted with different nucleoside monophosphate morpholidates to form ADP-, CDP-, GDP- and UDP-sulfoquinovose. Analytical and preparative HPLC of these nucleotides was performed on reversed-phase columns using volatile buffer systems as eluant. The
Lipid compositions of undifferentiated maize (Zea mays) chloroplasts, capable of fixing CO(2), were compared with the lipid compositions of mature chloroplasts, which do not fix CO(2), located in both the mesophyll and bundle sheath cells. The major lipids found in all three chloroplast types were
During short term labeling of expanding leaves of seven plant species with [1-(14)C]acetate, 35 to 64% of the label incorporated into lipids was found in phosphatidylcholine and 5 to 24% in phosphatidylglycerol. In pumpkin, sunflower, broad bean, and maize, only 4 to 12% of the label was found in
Intact spinach (Spinacia oleracea) chloroplasts, pulse-labeled with [(14)C]acetate, desaturate newly formed fatty acids as ester groups of monogalactosyl diacylglycerol in a subsequent chase in the dark. Rupture of pulse-labeled chloroplasts by addition of a detergent solution
Isolated spinach chloroplasts have been found to incorporate 35SO4 into the plant sulfolipid, sulfoquinovosyldiacylglycerol, at rates of up to 700 pmol mg chlorophyll-1 h-1. The reaction is light-dependent, requires that the chloroplasts be intact, and is slightly stimulated by ATP and UTP.